Being overweight hampers body’s immune response to SARS-CoV-2

Queensland University researchers have discovered that being overweight can hinder the body’s ability to produce antibodies in response to SARS-CoV-2 infection. However, this impairment does not affect the protective effects of COVID-19 vaccination.

This research sheds light on the complex relationship between weight and the body’s immune response to COVID-19, emphasising the importance of vaccination and tailored health strategies for overweight individuals.

Marcus Tong, a PhD candidate at the School of Chemistry and Molecular Biosciences and the lead researcher of the study, emphasised that their findings build upon previous research highlighting the impact of COVID-19 on overweight individuals. Tong stated, “We’ve previously shown that being overweight – not just being obese – increases the severity of SARS-CoV-2. But this work shows that being overweight creates an impaired antibody response to SARS-CoV-2 infection but not to vaccination.”

The research team collected blood samples from individuals who had recovered from COVID-19 and had not experienced reinfection during the study period, which spanned approximately 3 months and 13 months post-infection.

“At 3 months post-infection, an elevated BMI was associated with reduced antibody levels,” Tong explained. “And at 13 months post-infection, an elevated BMI was associated with both reduced antibody activity and a reduced percentage of the relevant B cells, a type of cell that helps build these COVID-fighting antibodies.”

Interestingly, the study revealed that an elevated BMI had no impact on the antibody response to COVID-19 vaccination, even approximately 6 months after the second vaccine dose was administered.

The research, published in Clinical & Translational Immunology, highlights the importance of these findings in shaping future health policies. Associate Professor Kirsty Short stressed the increased risk overweight individuals may face in terms of severe disease and impaired immune response, potentially leading to reinfection. Therefore, she emphasized the crucial role of vaccination for this group, stating, “It makes it more important than ever for this group to ensure they’re vaccinated.”

Dr. Short also suggested that these findings raise questions about current policies regarding boosters and lockdowns from a public health perspective. She proposed the need for more personalized recommendations for overweight individuals, both in managing COVID-19 and preparing for future pandemics.

Furthermore, the data underscores the urgency of improving SARS-CoV-2 vaccination efforts in low-income countries, where a significant percentage of the population is overweight and relies on infection-induced immunity.